Department of Agriculture and Food Engineering, Indian Institute of Technology (IIT), Kharagpur, India 721 302.
Environ Technol. 2012 Jun;33(10-12):1445-53. doi: 10.1080/09593330.2011.633103.
The performance of a laboratory-scale upflow anaerobic sludge blanket (UASB) reactor and a duckweed pond containing Lemna gibba was investigated for suitability for treating effluent for use in aquaculture. While treating low-strength sewage having a chemical oxygen demand (COD) of typically less than 200 mg/L, with an increase in hydraulic retention time (HRT) from 10.04 to 33.49 h, COD removal efficiency of the UASB reactor decreased owing to a decrease in organic loading rate (OLR) causing poor mixing in the reactor. However, even at the lower OLR (0.475 kg COD/(m3 x d)), the UASB reactor gave a removal efficiency of 68% for COD and 74% for biochemical oxygen demand (BOD). The maximum COD, BOD, ammonia-nitrogen and phosphate removal efficiencies of the duckweed pond were 40.77%, 38.01%, 61.87% and 88.57%, respectively. Decreasing the OLR by increasing the HRT resulted in an increase in efficiency of the duckweed pond for removal of ammonia-nitrogen and phosphate. The OLR of 0.005 kg COD/(m2 x d) and HRT of 108 h in the duckweed pond satisfied aquaculture quality requirements. A specific growth rate of 0.23% was observed for tilapia fish fed with duckweed harvested from the duckweed pond. The economic analysis proved that it was beneficial to use the integrated system of a UASB reactor and a duckweed pond for treatment of sewage.
采用上流式厌氧污泥床（UASB）反应器和浮萍池塘（内含浮萍）作为中试规模设备，研究其处理经处理后可用于水产养殖的污水的适用性。在处理化学需氧量（COD）一般低于 200mg/L 的低浓度污水时，随着水力停留时间（HRT）从 10.04 小时增加到 33.49 小时，UASB 反应器的 COD 去除效率由于有机负荷率（OLR）的降低而降低，这导致反应器中的混合效果不佳。然而，即使在较低的 OLR（0.475kgCOD/（m3xd））下，UASB 反应器对 COD 和生化需氧量（BOD）的去除效率分别达到 68%和 74%。浮萍池塘的最大 COD、BOD、氨氮和磷酸盐去除效率分别为 40.77%、38.01%、61.87%和 88.57%。通过增加 HRT 降低 OLR 会提高浮萍池塘去除氨氮和磷酸盐的效率。浮萍池塘的 OLR 为 0.005kgCOD/（m2xd），HRT 为 108 小时，满足水产养殖质量要求。从浮萍池塘收获的浮萍喂养的罗非鱼的特定生长率为 0.23%。经济分析证明，使用 UASB 反应器和浮萍池塘的组合系统处理污水是有益的。
